Multicomponent aqueous based liquid compositions having commercial and industrial applications, containing materials that cause or support the formation and growth of microorganisms which result in the breakdown and/or reduction of the functional effectiveness of the composition are well known. Such water based multicomponent compositions include, for example, aqueous based metalworking fluids, hydraulic fluids, cooling fluids, damping fluids and heat transfer fluids. Aqueous based metalworking fluids and hydraulic fluids have been gaining in importance over non-aqueous metalworking and hydraulic fluid compositions because of their economic, environmental and safety advantages. Water based metalworking fluid compositions have been used in chip forming and non-chip forming metalworking processes well known in the art such as drilling, tapping, broaching, grinding, rolling, drawing, spinning, milling, bending and stamping. The demand for aqueous based hydraulic fluid compositions such as may be used in hydraulic cylinders and pumps, has been increasing because of the economic and safety (e.g. high non-flammability) advantages of such fluids over non-aqueous, oil type hydraulic fluids. The increasing cost and disposal problems of non-aqueous, oil based functional fluid compositions has accelerated the demand for aqueous based functional fluid compositions.
The multicomponent water based functional fluid composition is however known to contain organic constituents that are subject to attack by microorganisms (e.g. bacteria, mold, fungus etc.) which leads to a breakdown (i.e. instability) of those constituents and the composition resulting in a loss in its functional effectiveness (e.g. rancidity, loss of friction reduction and corrosion control). This attack by microorganisms has been the focus of much concern and activity in the art pertaining to aqueous functional fluid compositions. Such concern and activity has lead to numerous prior art compounds and compositions for preventing or retarding the microorganism attack on aqueous functional fluid compositions.
Formaldehyde and formaldehyde producing compounds have been employed in the art for some time now to combat the attack on many organic constituents in commercial and industrial aqueous systems by a variety of microorganisms. Although formaldehyde and formaldehyde producing compounds have been found to be effective in a number of instances, their usage in aqueous systems is decreasing. Considerable work has been done in the art to combat the microbial attack on commercial and industrial aqueous based fluids using compounds other than formaldehyde and formaldehyde producing compounds.
Iodopropargyl compounds have been disclosed as microbiocides for a variety of systems including paints, wood, adhesives, glue, paper, textiles, plastics, cardboard, lubricants, cooling water, cutting fluids and metalworking fluids (U.S. Pat. No. 5,179,127 to A. C. Hsu). S. E. Sherba et.al. (U.S. Pat. No. 5,156,665) have taught a synergistic combination of 2-alkyl-3-isothiazolones and certain iodopropargyl compounds (e.g. N-iodopropargyloxycarbonyl glycine methyl ester) for use in fabric, leather, wood, paper, fuel and metalworking fluid (unspecified). The combination of 3-iodo-2-propynyl butyl carbamate and phenyl-(2-cyano-2-chlorovinyl) sulfone in water containing system has been reported by D. K. Donofrio et.al. in U.S. Pat. No. 5,147,891. A combination of a carbamate and a sulfamide as a bactericidal composition for water containing systems has been employed by W. K. Whitekettle et.al. (U.S. Pat. No. 5,147,890). The inhibition of microbial growth in oil in water emulsion metalworking fluids by a combination of the reaction product of a salt of copper and an alkanolamine and the product of the reaction between a salt of molybdenum and an alkanolamine has been disclosed by T. Mauthner et.al. (U.S. Pat. No. 5,106,519). A 3oiodopropargyl ester of carbamic acid has been used to combat micro-organism growth in aqueous based paint and metalworking fluid (U.S. Pat. No. 4,945,109 S. R. Rayudu). N-hexyl-ethanol amine has been reported to inhibit microbial growth in industrial water based coolants and in cutting fluids or metalworking fluids (U.S. Pat. No. 4,925,582 - E. O. Bennett and U.S. Pat. No. 4,749,503 E. O. Bennett et.al.). The addition of molybdenum or tungsten thiocarbamate to lubricating oils or automatic transmission fluids has been reported by W. C. Ward (U.S. Pat. No. 4,846,983). Latex paint formulations containing a 1-halogen substituted lower molecular weight alkyne (e.g. butyl urethane of 4-hydroxy-1-iodopropyne) has been described by W. Singer in U.S. Pat. No. 3,923,870.
Orthopenylphenol, a material difficult to solubilize in water, has in some systems afforded good fungal control, but has offered inefficient bacterial control. Copper and copper compounds have been employed in the art to control odors developed by micro-organisms in some aqueous systems but has provided poor control over bacteria growth. Admixtures of methylchoroisothiazoline and methyl isothiazolone have been employed in the art to control micro-organism growth in aqueous systems but has exhibited instability in alkaline systems (e.g. alkaline aqueous metalworking fluids). Alkyl parabens (e.g. methyl, ethyl and propyl) have exhibited good antimicrobial activity but are known to be expensive, and have poor water solubility.
Generally biocides are sought that have a broad spectrum of activity against micro-organism growth and wide applicability in respect to the types and compositions of the systems they are intended to protect against attack by plant and animal micro-organisms. Some of the bacteria against which the biocides are directed include Salmonella choleraesuis, Serratia marcescens, Klebsiella pneumoniae, Enterobacter aerogenes, Aerobacter aerogenes, Pseudomonas subtilis, Proteus vulgaris, Streptococcus faecalis, Pseudomonas aeruginosa, Escherichia coli and Staphlococcus aureus. Fungi and yeasts against which these agents may be directed can include Aspergillus niger, Candida ablicans, Lentinus lepideus, Gluoeophyllum trabeum, Coroiulus yersicolor, Trichoderms viride, Alternario alternata, Penicillium decembens, Botrytis cinerea, Collectotricyma coffeanum, Verticillium dahliae and Trichophyton mentagrophytes.
In aqueous based functional fluids, such as for example aqueous based metalworking fluid and aqueous based hydraulic fluid compositions, prior art biocides (i.e. agents to prevent or retard the growth of micro-organisms and the attack of micro-organisms on components of aqueous based functional fluid compositions) have been found to be lacking in a combination of effectiveness, stability, ease of use and economy. Thus there has been a need to overcome these problems in formulating operationally effective, long life and cost effective aqueous based functional fluids.
It is an object of this invention to provide an aqueous based functional fluid composition having a compatible, stable, effective agent to combat the growth of micro-organisms therein and the attack of microorganisms on components thereof.
It is another object of this invention to provide an aqueous based functional fluid composition having high resistance to the growth of and attack by micro-organisms.
A further object of this invention is to provide an aqueous functional fluid composition having resistance to the growth of and attack by micro-organisms while being free of formaldehyde and formaldehyde producing biocide agents.
A still further object of this invention is to provide an aqueous based metalworking fluid composition that is highly resistant to the growth of and attack by micro-organisms.
These and other objects, as will be apparent to those skilled in the art, are achieved in accordance with the invention disclosed and claimed herein.